A liquid chromatography system including a solvent delivery system, a sample delivery system in fluidic communication with solvent delivery system, a liquid chromatography column located downstream from the solvent delivery system and the sample delivery system, a detector located downstream from the liquid chromatography column, a thermal chamber housing at least one of the solvent delivery system, the sample delivery system, the liquid chromatography column and the detector, an engine configured to control the temperature in the thermal chamber, a heatsink operably connected to the engine, a first temperature sensor in the thermal chamber, a second temperature sensor, and a computer system configured to receive temperature information from each of the first and second temperature sensors, and implement a method for controlling temperature in the thermal chamber.

A gas chromatograph includes a sample introduction portion and a heater block. A contact portion is fit into a first recess of a main body of the sample introduction portion. The heater block is fixed to and positioned with respect to the main body of the sample introduction portion by directly coming into contact with the contact portion provided on the main body of the sample introduction portion. For this reason, the heater block may be surely positioned with respect to the sample introduction portion. In addition, the heater block may be positioned without providing a member such that heat from the heater block is transferred to the outside and lost, and thus the sample introduction portion may be efficiently heated.

A method for screening pesticide residues in medicine food homology (MFH) characteristic agricultural products includes step 1, a liquid chromatography-mass spectrometry database of pesticides is constructed, standard solution are prepared for the pesticides and liquid chromatography and mass spectrometry are used to detect the standard solutions; step 2, a sample is processed and then is detected to obtain a liquid chromatography-mass spectrogram; step 3, the liquid chromatography-mass spectrogram obtained from step 2 and liquid chromatography-mass spectrograms in the liquid chromatography-mass spectrometry database obtained from step 1 are compared and analyzed individually. The advances are as follows: a high-resolution rapid method for no less than 300 pesticide residues has been established, the method has high qualitative accuracy, controls the probability of quality accidents to almost zero, and provides reliable technical support for customs supervision of import and export of the MFH agricultural products.

The present invention belongs to the field of drug preparation and detection, and particularly discloses a preparation method for a Eucommia ulmoides Oliv. leaf extract. The extract is obtained from Eucommia ulmoides Oliv. leaves (the mixture of the Eucommia ulmoides Oliv. leaves and Eucommia ulmoides Oliv. male flower) by enzymolysis and extraction of ethanol and water, and can effectively solve the problem that the extract is not easy to spray dry (the Eucommia ulmoides Oliv. leaves contain colloidal substances). The pharmacodynamic experiment proves that the Eucommia ulmoides Oliv. leaf extract has good effect of protecting the health of the renal function. The present invention also develops a detection method for the extract, which not only realizes the quality control of the extract, but also has the advantages of good repeatability and stability.

Thermal isolation chambers that can be used to heat or cool a chromatography column are described. Certain configurations include at least one plate and an insulative barrier. The plate and insulative barrier can form a cyclical air flow path such that air in the cyclical air flow path can be provided to a chromatography column to remove heat from the chromatography column. The heat can be transferred to the plate. Systems including the thermal isolation chambers, and methods of using the thermal isolation chambers to perform chromatographic separations are also described.

To analytically determine concentration of dissolved gases in a water pipeline, a water sample is drawn from a source carrying water with dissolved gas, through a water source port of a four-way valve. The water sample is flowed from the water source port towards a syringe port of the valve and into a syringe fluidically coupled to the syringe port to hold the water sample. Inert gas is drawn through an inert gas port of the valve from an inert gas source and is flowed from the inert gas port towards the syringe port and into the syringe. A mixture of the water sample and the inert gas is flowed from the syringe port towards an analyzer port of the valve and into an analyzer fluidically coupled to the analyzer port.

Techniques are described for accelerating thermal equilibrium in a chromatographic column. An apparatus comprises a chromatography column, and a plurality of temperature control units in thermal contact with the chromatography column. A method of performing liquid chromatography comprises setting an inlet of a chromatography column to a first temperature using a first temperature control unit in thermal contact with said inlet, setting an outlet of the chromatography column to a second temperature using a second temperature control unit in thermal contact with the outlet, wherein the first temperature is less than the second temperature; and injecting a sample into a liquid stream that flows through the chromatography column after the inlet is set at the first temperature and the outlet is at the second temperature.

A gas chromatography instrument comprising a first autoinjector in communication with a first column, a second autoinjector in communication with a second column, a first flame ionization detector in communication with the first column, a second flame ionization detector in communication with the second column, wherein the first column is housed in a first compartment and the second column is housed in a second compartment.

The technology relates to a recycling chromatography method. A sampled is injected into a mobile phase flow stream of a liquid chromatography system creating a combined flow stream. The liquid chromatography system includes at least two columns positioned in series, a valve in fluid communication with the at least two columns, and a detection cell positioned between the at least two columns. The combined flow stream is flowed through the at least two columns and chromatographic peaks of the sample are monitored by the detection cell. The detection cell is configured to measure resolution and width of the chromatographic peaks and automatically switch the valve from a first position to a second position when the measured resolution is less than a desired resolution, the measured width is less than a maximum combined peak width, and a switch count is less than a predetermined maximum number of switches.

An apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column wherein the insulating member is formed from a vacuum chamber surrounding the chromatography column. Another apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column, wherein the insulating member includes aerogel. Also described is a method of insulating a chromatography column comprising forming a jacket surrounding the chromatography column, and creating a vacuum chamber in an area between the jacket and the chromatography column.